Joint for artificial limbs.



N0. 817,785. PATENTED APR. 17, 1906 G. E. KRITSGH.

JOINT FOR ARTIFICIAL LIMBS.

APPLICATION FILED FEB. 23. 1906.

CHARLES E. KRITSCH, OF WVASHINGTON, DISTRIC" OF COLUMBIA.

JOINT FOR ARTIFICIAL LIIVIBS.

Specification of Letters Patent.

iratented April 17, 1906.

Application filed February 23, 1906. Serial No. 302,546.

T0 at whom, it may concern:

Be it known that I, CHARLES E. Knrrson, a citizen of the United States,residing at \Vashington, District of Columbia, have invented certain newand useful Improvements in Joints for Artificial Limbs; and I do herebydeclare the following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same, reference being had to theaccompanying drawings, and to the letters of reference marked thereon,which form a part of this specification.

This invention relates to new and useful improvements in flexible knee-joints for artificial legs, and comprises a simple and efficient meansfor connecting the sections of the limb by the employment of a fewparts, dispensing with pawls and other deviceswhich are apt to creak andrattle.

More specifically, the invention consists in the provision of twopivotal knee-joint members one of which is provided with 'a chamberedportion the bottom of which, at one end thereof, is provided with anaperture adapted to receive a bushing upon the other member, the partsbeing held together by means of a screw passing through the bushing andengaging a nut upon the opposite end thereof, and in the provision of acoiled spring which is anchored at one end within said casing orchambered portion and its other end fastened to the pivotal member,thereby normally holding the two members in alinement with each other.

My invention consists, further, in various details of construction andcombinations and arrangements of parts, which will be hereinafter fullydescribed.

My invention is illustrated in the accompanying drawings, in which- Fiure 1 is a side elevation of the two joint mem ers pivoted together,showing in dotted outlines the positions that one of the joints mayassume. Fig. 2 is a cross-sectional view on line 2 2 of Fig. 1. Fig. 3is a plan view with the plate or cover to the casing removed; and Fig. 4is a detail view of one of the joint members detached, showing thebushing fixed thereto.

Reference now being had to the details of the drawings by letter, A andB designate two plates, the former of which is provided with a chamberedportion A, the bottom wall of which extends beyond the flanges on theopposite sides thereof and is centrally apertured, as at A for thereception of one end of the boss B, which projects about an aperture Bformed in one end of the member B. Said boss projects from either sideof the member to which it is fixed, and one end of the boss has abearing in the aperture in the member A, while the other end of the bosshas a bearing in an aperture C, formed in the end of the cover C. Saidcover has two recessed portions D upon opposite edges thereof adapted toreceive the ribs E, which proj ect from the upper edges of the sidewalls of flanges of the recess formed in plate A. A boss F projects fromone side of the plate A, adjacent to the rear end of the recess therein,and is adapted to engage an aperture H, formed in said. cover. Said bossupon the plate A has a central threaded aperture adapted to receive ascrew 0, having a head which engages about the periphery of the openingin one end of said cover, while a screw Q is fitted within the centralopening in the boss upon the plate B and is adapted to engage a threadedaperture in a socket J, inserted in one end of the boss. Mounted withinsaid recess in the plate A is a spring T, one end of which is fastenedto a screw R, while the opposite end of the spring is fastened to theend of the plate B and is adapted to normally hold the inner end of saidplate B in contact with a stop I, fastened within the recess. I

' It will be noted that the outer edge of the pivotal end of the plate Bis rounded and is flush with the edges of the cover and the projectingpart of the plate A, to which it is pivoted, thereby affording a jointedplate without any projecting parts which are liable to catch uponclothing or other objects.

From the foregoing it will be noted that by the provision of aknee-joint as shown and described a simple and eificient means isafforded for connecting the two plates with a minimum number of parts,which is simple in construction, and so arranged that the swingingmovements of the plates in opposite directions may be limited.

WVhat I claim is 1. A knee-joint for artificial legs, comprising twoplates adapted for attachment to the sections of the leg, one of saidplates having an aperture adjacent to one end, a hollow boss mounted insaid aperture and to which the other plate has pivotal connection, aspring connecting the plates, and a stop carried by one of the platesand adapted to limit l the throw ol the plates in one direction, as i"set forth. I 2. A knee-joint for artificial legs, comprisl ing twoplates, one of Which has a hollow boss projecting from opposite facesthereof, the other plate being recessed with a projection at the end ofsaid recess which is apertnred to receive one end of the boss, at stopmounted i IO in the recess and against which an end of the lboss-carrying plate is adapted to contact, a i

spring mounted within said recess and connecting said plates, a closurefor the recess, a screw passing through said boss, and a nut engagingsaid screw, as set forth.

In testimony whereof I hereunto afliX my signature in the presence oftwo witnesses.

CHARLES E. KRITSCH.

Witnesses:

A. L. HoUGH, FRANKLIN H. HoUen.

